From patchwork Tue Dec 1 08:53:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 336907 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0D72AC83014 for ; Tue, 1 Dec 2020 08:56:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A86CD2220B for ; Tue, 1 Dec 2020 08:56:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Hw+qcDUW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387655AbgLAI4M (ORCPT ); Tue, 1 Dec 2020 03:56:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:59034 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387640AbgLAI4I (ORCPT ); Tue, 1 Dec 2020 03:56:08 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1E82622259; Tue, 1 Dec 2020 08:55:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606812927; bh=CvzfrnGumdA7r8ogxk4oIcN74VmmIiyD7gYxBF/TlNM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Hw+qcDUW8jPdoZxQmyk1vaEiN51WcyKXdS53PExrqcYNt3ObA9Ntwe6f3TMUkPFhu ieWp2omL/e1yL/cI1tIm6HG7CBO2gWzpBB/zZeGLaXy6m/J66vH5qLvq9QgAUbGW2c zsfFu2QR4rNMKNi5e46uN1Eyb3VDMwphW+vjk6D4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Can Guo , Stanley Chu , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 4.9 23/42] scsi: ufs: Fix race between shutdown and runtime resume flow Date: Tue, 1 Dec 2020 09:53:21 +0100 Message-Id: <20201201084643.883554004@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201201084642.194933793@linuxfoundation.org> References: <20201201084642.194933793@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Stanley Chu [ Upstream commit e92643db514803c2c87d72caf5950b4c0a8faf4a ] If UFS host device is in runtime-suspended state while UFS shutdown callback is invoked, UFS device shall be resumed for register accesses. Currently only UFS local runtime resume function will be invoked to wake up the host. This is not enough because if someone triggers runtime resume from block layer, then race may happen between shutdown and runtime resume flow, and finally lead to unlocked register access. To fix this, in ufshcd_shutdown(), use pm_runtime_get_sync() instead of resuming UFS device by ufshcd_runtime_resume() "internally" to let runtime PM framework manage the whole resume flow. Link: https://lore.kernel.org/r/20201119062916.12931-1-stanley.chu@mediatek.com Fixes: 57d104c153d3 ("ufs: add UFS power management support") Reviewed-by: Can Guo Signed-off-by: Stanley Chu Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/ufs/ufshcd.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index ad5f2e2b4cbaf..ad80e4223c2d3 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -6521,11 +6521,7 @@ int ufshcd_shutdown(struct ufs_hba *hba) if (ufshcd_is_ufs_dev_poweroff(hba) && ufshcd_is_link_off(hba)) goto out; - if (pm_runtime_suspended(hba->dev)) { - ret = ufshcd_runtime_resume(hba); - if (ret) - goto out; - } + pm_runtime_get_sync(hba->dev); ret = ufshcd_suspend(hba, UFS_SHUTDOWN_PM); out: